Clock



FIG. 1 is a front perspective view of a clock showing my new design;

FIG. 2 is a front view thereof; and,

FIG. 3 is a right side view thereof, the left side, top, and bottomviews being substantial mirror images thereof.

The rear of the clock, not shown, forms no part of the claimed design.

CLAIM The ornamental design for a clock, as shown and described.